A Pediatric Rheumatology Tissue Repository is proposed as a resource that will be available to investigators in the research base in Cincinnati and will provide a unique resource for pediatric rheumatology nationally The Tissue Repository will provide for uniform acquisition and storage of clinical samples. The principal functions of the Repository are: To collect, process and maintain biological specimens from patients with pediatric rheumatological and related musculoskeletal conditions, as well as relevant control populations (for both case control and family studies). To allow systematic access to biological samples for investigators conducting basic and translational studies in pediatric rheumatological diseases. To assist in study design and sample selection, based on available samples, to facilitate research and conserve limited resources.